Zunyang Ke, Yu Wang and Zhongming Li

Anion-exchange chromatography is a key capture step in downstream processing plasmid DNA (pDNA). Separation of pDNA using traditional particle-based anion-exchange supports is usually slow and has a low capacity for pDNA due to steric exclusion effects. Due to convective mass transfer properties, and large flow-through channels for binding large biomolecules, monoliths have been shown to provide a fast and efficient alternative for pDNA purification. This study describes the use of monoliths for purification of a therapeutic pDNA vaccine against multidrug resistant tuberculosis (MDR TB).

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J. Ruscic, I. Gutiérrez-Aguirre, M. Tusek Znidaric, S. Kolundzija, A. Slana, M. Barut, M. Ravnikar, M. Krajacic
Journal of Chromatography A, 1388 (2015) 69–78

The emergence of next-generation "deep" sequencing has enabled the study of virus populations with much higher resolutions. This new tool increases the possibility of observing mixed infections caused by combinations of plant viruses, which are likely to occur more frequently than previously thought. The bio-logical impact of co-infecting viruses on their host has yet to be determined and fully understood, and the first step towards reaching this goal is the separation and purification of individual species. Ion-exchange monolith chromatography has been used successfully for the purification and concentration of different viruses, and number of them have been separated from plant homogenate or bacterial and eukaryoticlysate. Thus, the question remained as to whether different virus species present in a single sample could be separated. In this study, anion-exchange chromatography using monolithic supports was optimized for fast and efficient partial purification of three model plant viruses: Turnip yellow mosaic virus, Tomato bushy stunt virus, and Tobacco mosaic virus. The virus species, as well as two virus strains, were separated from each other in a single chromatographic experiment from an artificially mixed sample. Based on A260/280 ratios, we were able to attribute specific peaks to a certain viral morphology/structure (icosa-hedral or rod-shaped). This first separation of individual viruses from an artificially prepared laboratory mixture should encourage new applications of monolithic chromatographic supports in the separation of plant, bacterial, or animal viruses from all kinds of mixed samples.

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D. Buzzi, A. Štrancar

Chimica Oggi-Chemistry Today; Vol 33(1) January/February 2015

The importance of the monitoring of a process all along its steps by means of PAT has been defined by FDA in 2002. How can be defined the product quality and what are the parameters that should be checked by means of different analysis techniques, being focused in particular on the application of high pressure liquid chromatography techniques (HPLC) as high value tool for the process monitoring. From the first introduction of Process Analytical Technology to the "state of the art": how can be PAT implemented in order to ensure the final product quality.

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J-P Pirnay et al.

Pharm Res, Springer, 14 Jan 2015

The worldwide antibiotic crisis has led to a renewed interest in phage therapy. Since time immemorial phages control bacterial populations on Earth. Potent lytic phages against bacterial pathogens can be isolated from the environment or selected from a collection in a matter of days. In addition, phages have the capacity to rapidly overcome bacterial resistances, which will inevitably emerge.
To maximally exploit these advantage phages have over conventional drugs such as antibiotics, it is important that sustainable phage products are not submitted to the conventional long medicinal product development and licensing pathway. There is a need for an adapted framework, including realistic production and quality and safety requirements, that allows a timely supplying of phage therapy products for 'personalized therapy' or for public health or medical emergencies.
This paper enumerates all phage therapy product related quality and safety risks known to the authors, as well as the tests that can be performed to minimize these risks, only to the extent needed to protect the patients and to allow and advance responsible phage therapy and research.

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A.M. Almeida, J.A. Queiroz, F. Sousa, A. Sousa

Journal of Chromatography B, 978–979 (2015) 145–150

The progress of DNA vaccines is dependent on the development of suitable chromatographic procedures to successfully purify genetic vectors, such as plasmid DNA. Human Papillomavirus is associated with the development of tumours due to the oncogenic power of E6 and E7 proteins, produced by this virus. The supercoiled HPV-16 E6/E7 plasmid-based vaccine was recently purified with the arginine monolith, with 100% of purity, but only 39% of recovery was achieved. Therefore, the present study describes the application of experimental design tools, a newly explored methodology in preparative chromatography, in order to improve the supercoiled plasmid DNA recovery with the arginine monolith, maintaining the high purity degree. In addition, the importance and influence of pH in the pDNA retention to the arginine ligand was also demonstrated. The Composite Central Face design was validated and the recovery of the target molecule was successfully improved from 39% to 83.5%, with an outstanding increase of more than double, while maintaining 100% of purity.

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H. M. Oksanen, A. Domanska, D. H. Bamford
Virology Volume 434, Issue 2, 20 December 2012

We report anion exchange chromatographic purification method powerful for preparation of virus particles with ultra pure quality. The technology is based on large pore size monolithic anion exchangers, quaternary amine (QA) and diethylaminoethyl (DEAE). These were applied to membrane-containing icosahedral bacteriophage PRD1, which bound specifically to both matrices. Virus particles eluted from the columns retained the ir infectivity, and were homogenous with high specific infectivity. The yields of infectious particles were up to 80%. Purified particles were recovered at high concentrations, approximately 5mg/ml, sufficient for virological, biochemical and structural analyses. We also tested the applicability of the monolithic anion exchange purification on a filamentous bacteriophage phi 05_2302. Monolithic ion exchange chromatography is easily scalable and can be combined with other preparative virus purification methods.

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J. Transfiguracion, A. P. Manceur, E. Petiot, C. M. Thompson, A. A. Kamen
Vaccine (2014)

The influenza virus continuously undergoes antigenic evolution requiring manufacturing, validation and release of new seasonal vaccine lots to match new circulating strains. Although current production processes are well established for manufacturing seasonal inactivated influenza vaccines, significant limitations have been underlined in the case of pandemic outbreaks. The World Health Organization called for a global pandemic influenza vaccine action plan including the development of new technologies. A rapid and reliable method for the quantification of influenza total particles is crucially needed to support the development, improvement and validation of novel influenza vaccine manufacturing platforms. This work presents the development of an ion exchange-high performance liquid chromatography method for the quantification of influenza virus particles. The method was developed using sucrose cushion purified influenza viruses A and B produced in HEK 293 suspension cell cultures. The virus was eluted in 1.5 M NaCl salt with 20 mM Tris–HCl and 0.01% Zwittergent at pH 8.0. It was detected by native fluorescence and the total analysis time was 13.5 min. A linear response range was established between 1 × 109 and 1 × 1011 virus particle per ml (VP/ml) with a correlation coefficient greater than 0.99. The limit of detection was between 2.07 × 108 and 4.35 × 109 whereas the limit of quantification was between 6.90 × 108 and 1.45 × 1010 VP/ml, respectively. The coefficient of variation of the intra- and inter-day precision of the method was less than 5% and 10%. HPLC data compared well with results obtained by electron microscopy, HA assay and with a virus counter, and was used to monitor virus concentrations in the supernatant obtained directly from the cell culture production vessels. The HPLC influenza virus analytical method can potentially be suitable as an in-process monitoring tool to accelerate the development of processes for the manufacturing of influenza vaccines.

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P. Leblebici, M. E. Leblebici, F. Ferreira-da-Silva, A. E.Rodrigues, L. S. Pais
Journal of Chromatography B, 962 (2014) 89-93

Monolithic columns have attracted significant attention for the purification of large biomolecules. In the present study, a step gradient elution method was evaluated for the separation of human immunoglobulinG (hIgG) into its subclasses on CIM (convective interaction media) r-protein A (recombinant protein A)monolithic column. hIgG was loaded onto the column and bound protein was eluted with a pH gra-dient. The subclass content of the eluted fractions was analyzed by enzyme-linked immunosorbentassay (ELISA). Results showed that separation of IgG3 from the other three subclasses can be success-fully achieved with high selectivity (100%) and throughput on monolithic media. It was also revealedthat enriched fractions of IgG1 and IgG2 could be obtained from purified hIgG in a 28 min long chro-matographic run. Three fractions with high IgG1 content (89.1%, 94.3% and 88.8%) were recovered. Furthermore, IgG2 was enriched to 64% successfully. A rapid step gradient elution scheme without any additives in buffers was proven to obtain enriched preparations of the two important subclasses with high throughput. The separation time can be reduced even more by increasing the flow rate without anyloss in selectivity, which will be beneficial in industrial scale applications.

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M. Pucic, A. Knezevic, J. Vidic, B. Adamczyk, M. Novokmet, O. Polasek, O. Gornik, S. Supraha-Goreta, M. R. Wormald, I. Redzic, H. Campbell, A. Wright, N. D. Hastie, J. F. Wilson, I. Rudan, M. Wuhrer, P. M. Rudd, Dj. Josic, and G. Lauc

Mol Cell Proteomics. Oct 2011; published online Jun 8, 2011

All immunoglobulin G molecules carry N-glycans, which modulate their biological activity. Changes in N-glycosylation of IgG associate with various diseases and affect the activity of therapeutic antibodies and intravenous immunoglobulins. We have developed a novel 96-well protein G monolithic plate and used it to rapidly isolate IgG from plasma of 2298 individuals from three isolated human populations. N-glycans were released by PNGase F, labeled with 2-aminobenzamide and analyzed by hydrophilic interaction chromatography with fluorescence detection. The majority of the structural features of the IgG glycome were consistent with previous studies, but sialylation was somewhat higher than reported previously.

Sialylation was particularly prominent in core fucosylated glycans containing two galactose residues and bisecting GlcNAc where median sialylation level was nearly 80%. Very high variability between individuals was observed, approximately three times higher than in the total plasma glycome. For example, neutral IgG glycans without core fucose varied between 1.3 and 19%, a difference that significantly affects the effector functions of natural antibodies, predisposing or protecting individuals from particular diseases. Heritability of IgG glycans was generally between 30 and 50%. The individual's age was associated with a significant decrease in galactose and increase of bisecting GlcNAc, whereas other functional elements of IgG glycosylation did not change much with age. Gender was not an important predictor for any IgG glycan. An important observation is that competition between glycosyltransferases, which occurs in vitro, did not appear to be relevant in vivo, indicating that the final glycan structures are not a simple result of competing enzymatic activities, but a carefully regulated outcome designed to meet the prevailing physiological needs.

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P. Gagnon

MSS2008

When monoclonal antibodies were first beginning to be commercialized, expression levels over 100 mg/L were considered outstanding, and cell culture was viewed as the bottleneck in manufacturing productivity. Antibody expression levels now commonly exceed 1 g/L and reports of 10 and 15 g/L have been recently announced. Downstream processing is now considered the bottleneck.

In one sense, the bottleneck is artificial. Cell culture production takes about two weeks (not counting preparation of seed stock) and purification takes about a week. In another sense, the bottleneck is real, and a genuine concern. Process time for the protein A capture step from 20,000 L of cell culture supernatant (CCS) commonly requires 72-96 hours. This represents multiple cycles. The long hold time for IgG produced in the early cycles increases the risk of degradation by proteolysis, deamidation, etc. It also increases the risk of contamination.

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C. Delattre, A.S. Kamalanathan, P. Michaud, M.A. Vijayalakshmi

Journal of Chromatography B, 861 (2008) 181–185

Selective purification of alpha-(1,4)-oligogalacturonides was investigated using several pseudobioaffinity chromatography matrix with aminoacid
L-histidine as pseudobiospecific ligand: (1) sepharose 4B-bisoxyran-histidine, (2) sepharose 4B-epoxy-histidine, (3) silica-oxyran-histidine and
(4) CIM-disk-EDA-histidine. These anionic oligosaccharides prepared by enzymatic and chemical cleavage of polygalacturonic acid were used
as models sugar in order to optimize the adsorption and elution parameters for a selective purification of bioactive oligouronides. Monolithic
CIM-disk chromatography is one of the fastest liquid chromatographic method using for separation and purification of biomolecules thanks to high
mass transfer rate. In this way, this new monolithic CIM-disk system with l-histidine immobilized: immobilized histidine affinity chromatography
(IHAC) constitutes a good tool allowing the fast and selective purification of bioactive oligouronides.

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F. W. Krainer, R. Pletzenauer, L. Rossetti, C. Herwig, A. Glieder, O. Spadiut
Protein Expression and Purification 95 (2014) 104–112

The plant enzyme horseradish peroxidase (HRP) is used in several important industrial and medical applications, of which especially biosensors and diagnostic kits describe an emerging field. Although there is an increasing demand for high amounts of pure enzyme preparations, HRP is still isolated from the plant as a mixture of different isoenzymes with different biochemical properties. Based on a recent next generation sequencing approach of the horseradish transcriptome, we produced 19 individual HRP isoenzymes recombinantly in the yeast Pichia pastoris. After optimizing a previously reported 2-step purification strategy for the recombinant isoenzyme HRP C1A by substituting an unfavorable size exclusion chromatography step with an anion exchange step using a monolithic column, we purified the 19 HRP isoenzymes with varying success. Subsequent basic biochemical characterization revealed differences in catalytic activity, substrate specificity and thermal stability of the purified HRP preparations. The preparations of the isoenzymes HRP A2A and HRP A2B were found to be highly interesting candidates for future applications in diagnostic kits with increased sensitivity.

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M. Banjac, E. Roethl, F. Gelhart, P. Kramberger, B. Lah Jarc, M. Jarc, A. Štrancar, T. Muster, M. Peterka
Vaccine 2014

We explored the possibilities for purification of various ΔNS1 live, replication deficient influenza viruseson ion exchange methacrylate monoliths. Influenza A ΔNS1-H1N1, ΔNS1-H3N2, ΔNS1-H5N1 and ΔNS1-influenza B viruses were propagated in Vero cells and concentrated by tangential flow filtration. All fourvirus strains adsorbed well to CIM QA and CIM DEAE anion exchangers, with CIM QA producing higherrecoveries than CIM DEAE. ΔNS1-influenza A viruses adsorbed well also to CIM SO3 cation exchanger atthe same pH, while ΔNS1-influenza B virus adsorption to CIM SO3 was not complete. Dynamic binding capacity (DBC) for CIM QA, DEAE and SO3 methacrylate monoliths for influenza A ΔNS1-H1N1virus were 1.9E + 10 TCID50/ml, 1.0E + 10 TCID50/ml and 8.9E + 08 TCID50/ml, respectively. Purification of ΔNS1 viruses on CIM QA was scaled up and reproducibility was confirmed. Yields of infectious viruson CIM QA were between 70.8 ± 32.3% and 87 ± 30.8%. Total protein removal varied from 93.3 ± 0.4% to98.6 ± 0.2% and host cell DNA removal efficiency was ranging from 76.4% to 99.9% and strongly dependedon pretreatment with deoxyribonuclease.

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M.-C. Claudepierrea, et al.

Journal of Virology, February 2014

To identify novel stimulators of the innate immune system, we constructed a panel of eight HEK293-cells lines, double-positive for human Toll-like receptors (TLR) and a NF-κB-inducible reporter gene. Screening a large variety of compounds and cellular extracts detected a TLR3 activating compound in a microsomal yeast extract. Fractionation of this extract identified a RNA molecule of 4.6 kb, named Nucleic Acid Band 2 (NAB2) that was sufficient to confer the activation of TLR3. Digests with single- and double-strand-specific RNases showed the double-strand nature of this RNA, and its sequence was found to be identical to the genome of the dsRNA L-BC virus of Saccharomyces cerevisiae. A large scale production and purification process of this RNA was established based on chemical cell lysis and dsRNA-specific chromatography. NAB2 complexed with the cationic lipid Lipofectin, but neither NAB2 nor Lipofectin alone, induced the secretion of IL-12(p70), IFNα, IP-10, Mip-1β and IL-6 in human monocyte-derived dendritic cells. While NAB2 activated TLR3, Lipofectin-stabilized NAB2 signaled also via the cytoplasmic sensor for RNA recognition MDA-5. Significant increase of RMA-MUC1 tumor rejection and survival was observed in C57BL/6 mice after prophylactic vaccination with MUC1-encoding MVA and NAB2+Lipofectin. This combination of immunotherapeutics strongly increased the percentage of infiltrating Natural Killer (NK) cells and plasmacytoid dendritic cells (pDCs) at the injection sites, cell types which can modulate innate and adaptive immune responses.

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M. Lock, M. R. Alvira, J. M. Wilson
HUMAN GENE THERAPY METHODS: Part B 23:56-64 (February 2012)

Advances in adeno-associated virus (AAV)-mediated gene therapy have brought the possibility of commercial manufacturing of AAV vectors one step closer. To realize this prospect, a parallel effort with the goal of everincreasing sophistication for AAV vector production technology and supporting assays will be required. Among the important release assays for a clinical gene therapy product, those monitoring potentially hazardous contaminants are most critical for patient safety. A prominent contaminant in many AAV vector preparations is vector particles lacking a genome, which can substantially increase the dose of AAV capsid proteins and lead to possible unwanted immunological consequences. Current methods to determine empty particle content suffer from inconsistency, are adversely affected by contaminants, or are not applicable to all serotypes. Here we describe the development of an ion-exchange chromatography-based assay that permits the rapid separation and relative quantification of AAV8 empty and full vector particles through the application of shallow gradients and a strong anion-exchange monolith chromatography medium.

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T. Čerk Petrič, P. Brne, B. Gabor, L. Govednik, M. Barut, A. Štrancar, L. Zupančič Kralj
Journal of Pharmaceutical and Biomedical Analysis 43 (2007) 243–249

In order to enable the detection of low abundance proteins from human plasma, it is necessary to remove high abundance proteins. Among them, human serum albumin and immunoglobulin G represent more than 75% of all such proteins. In this paper, the characterization of short monolithic columns was performed followed by the optimization of a multidimensional approach, known as conjoint liquid chromatography, to deplete human serum albumin and immunoglobulin G from a human plasma sample. Two different chromatographic modes were used: ion-exchange chromatography and affinity chromatography. A monolithic stationary phase (convective interaction media disk) bearing strong anion-exchange groups and another immobilized with protein G were placed in series into one housing. The optimal binding conditions were found that removed a majority of human serum albumin and immunoglobulin G from the human plasma sample. This method was compared to the depletion using a combination of pseudo-affinity and affinity columns. The results of the human serum albumin and immunoglobulin G depletion were confirmed by 2D electrophoresis. It has been shown that anion-exchange and affinity chromatography using convective interaction media monolithic columns can represent an efficient complementary technique for human serum albumin and immunoglobulin G removal from human plasma.

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Roy N D‘Souza, Ana M Azevedo, M Raquel Aires-Barros, Nika Lendero Krajnc, Petra Kramberger, Maria Laura Carbajal, Mariano Grasselli, Roland Meyer & Marcelo Fernández-Lahore

Vol. 1, No. 5, Pharmaceutical Bioprocessing (2013)

Downstream processing is currently the major bottleneck for bioproduct generation. In contrast to the advances in fermentation processes, the tools used for downstream processes have struggled to keep pace in the last 20 years. Purification bottlenecks are quite serious, as these processes can account for up to 80% of the total production cost. Coupled with the emergence of new classes of bioproducts, for example, virus-like particles or plasmidic DNA, this has created a great need for superior alternatives. In this review, improved downstream technologies, including aqueous two-phase systems, expanded bed adsorption chromatography, convective flow systems, and fibre-based adsorbent systems, have been discussed. These adaptive methods are more suited to the burgeoning downstream processing needs of the future, enabling the cost-efficient production of new classes biomaterials with a high degree of purity, and thereby hold the promise to become indispensable tools in the pharmaceutical and food industries.

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E. Maksimova, E. Vlakh, E. Sinitsyna, T. Tennikova
J. Sep. Sci. 2013, 36, 3741–3749

Ultrashort monolithic columns (disks) were thoroughly studied as efficient stationary phases for precipitation–dissolution chromatography of synthetic polymers. Gradient elution mode was applied in all chromatographic runs. The mixtures of different flexible chain homopolymers, such as polystyrenes, poly(methyl methacrylates), and poly(tert-butylmethacrylates) were separated according to their molecular weights on both commercial poly(styrene-co divinylbenzene).
disks (12 id × 3 mm and 5 × 5 mm) and lab-made monolithic columns (4.6 id × 50 mm) filled with supports of different hydrophobicity. The experimental conditions were optimized to reach fast and highly efficient separation. It was observed that, similar to the separation of monoliths of other classes of (macro)molecules (proteins, DNA, oligonucleotides), the length of column did not affect the peak resolution.
A comparison of the retention properties of the poly(styrene-co-divinylbenzene) diskshaped monoliths with those based on poly(lauryl methacrylate-co-ethylene dimethacrylate), poly(butyl methacrylate-co-ethylene dimethacrylate), and poly(glycidyl methacrylate-co-ethylene dimethacrylate) supports demonstrated the obvious effect of surface chemistry on the resolution factor. Additionally, the results of the discussed chromatographic mode on the fast determination of the molecular weights of homopolymers used in this study were compared to those established by SEC on columns packed with sorbent beads of a similar nature to the monoliths.

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M. V. Volokitina, E. G. Vlakh, G. A. Platonova, D. O. Vinokhodov, T. B. Tennikova
J. Sep. Sci. 2013, 36, 2793-2805

Two ribonuclease A bioreactors based on lab-made macroporous monolithic columns and intended for polynucleotide degradation were prepared using in situ free-radical polymerization. Different methods of enzyme immobilization were applied. In the first case, the biocatalyst molecule was attached to the solid surface via direct covalent binding, while in the second bioreactor the flexible-chain synthetic polymer was used as an intermediate spacer. The effect of temperature, substrate flow rate, and loaded sample volume on the biocatalytic efficiency of the immobilized enzyme was examined. The kinetic parameters of the enzymatic degradation of synthetic polycytidylic acid were calculated and compared to those found for hydrolysis with soluble ribonuclease A. The monitoring of substrate splitting was carried out by means of fast anion-exchange HPLC on an ultra-short monolithic column (disk) using off- and on-line analytical approaches.

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E. A. Ponomareva, M. V. Volokitina, D. O. Vinokhodov, E. G. Vlakh, T. B. Tennikova

Anal Bioanal Chem (2013) 405:2195–2206

Immobilized enzyme reactors (IMERs) produced by the covalent attachment of ribonuclease A to macroporous
methacrylate-based monolithic supports using different experimental approaches are discussed and compared. Enzyme immobilization was carried out by direct covalent binding, as well as through attachment via a polymer spacer. The kinetic properties of an IMER operating in either recirculation mode or zonal elution mode were studied. Additionally, the effect of flow rate on the bioconversion efficiency of each IMER sample was examined.

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